On-Chip Distributed Power Amplifier and On-Chip or In-Package Antenna for Performing Chip-To-Chip and Other Communications

ABSTRACT

A transmitter front-end for wireless chip-to-chip communication, and potentially for other, longer range (e.g., several meters or several tens of meters) device-to-device communication, is disclosed. The transmitter front-end includes a distributed power amplifier capable of providing an output signal with sufficient power for wireless transmission by an on-chip or on-package antenna to another nearby IC chip or device located several meters or several tens of meters away. The distributed power amplifier can be fully integrated (i.e., without using external components, such as bond wire inductors) on a monolithic silicon substrate using, for example, a complementary metal oxide semiconductor (CMOS) process.

FIELD OF THE INVENTION

This application relates generally to wireless communication and, morespecifically, to wireless chip-to-chip communication and other, longerrange, communication.

BACKGROUND

Many devices today include multiple integrated circuit (IC) chips tocarry out their designed for functionalities. These IC chips often needto communicate with each other at very high data rates. For example,complex devices can include several IC chips on a printed-circuit board(PCB) that are required to communicate with each other at ratesexceeding several gigabits per second (Gb/s), and these rates continueto increase with each new generation of devices. At such high rates,communication over electrical traces on a PCB becomes difficult due to,for example, impedance mismatches, the skin effect, and dielectricabsorption, all of which lead to distortion and/or attenuation of atransmitted signal. Moreover, depending on the number of IC chips used,routing of electrical traces between the IC chips can be difficult on aPCB with limited area.

Wireless communication can be used to overcome the problems ofelectrical interconnection described above. For example, wirelesscommunication is generally not constrained by PCB area limitations andenough unlicensed wireless spectrum exists to accommodate high datarates in the multi Gb/s range. In particular, there is 7 GHz of spectrumavailable for unlicensed wireless communication in the 60 GHz band, from57-64 GHz in the United States and Canada and from 59-66 GHz in Japan.This spectrum can be used to accommodate high data rate wirelesschip-to-chip communications in the multi Gb/s range.

However, for any such wireless chip-to-chip communication solution, andpotentially for other, longer range, communication solutions (e.g.,several meters or several tens of meters) for device-to-devicecommunication, it is desirable that the required hardware be compact andcheap. Current solutions for wireless chip-to-chip and device-to-devicecommunication typically fail to achieve one or both of these oftencompeting criteria by using off-chip components and/or expensive ICprocesses, such as Gallium Arsenide (GaAs).

BRIEF DESCRIPTION OF THE DRAWINGS/FIGURES

The accompanying drawings, which are incorporated herein and form a partof the specification, illustrate the embodiments of the presentdisclosure and, together with the description, further serve to explainthe principles of the embodiments and to enable a person skilled in thepertinent art to make and use the embodiments.

FIG. 1 illustrates a multi-chip device in which embodiments of thepresent disclosure can operate.

FIG. 2 illustrates a block diagram of a transmitter front-end inaccordance with embodiments of the present disclosure.

FIG. 3 illustrates a schematic diagram of a transmitter front-end withan on-chip antenna in accordance with embodiments of the presentdisclosure.

FIG. 4 illustrates an implementation of a power amplifier in accordancewith embodiments of the present disclosure.

FIG. 5 illustrates a layout of an impedance transformer, power combiner,and on-chip antenna in accordance with embodiments of the presentdisclosure.

FIG. 6 illustrates a transmitter front-end with distributed poweramplifiers and a phased-array of on-chip antennas in accordance withembodiments of the present disclosure.

FIG. 7 illustrates a transmitter front-end with distributed poweramplifiers and an on-package antenna in accordance with embodiments ofthe present disclosure.

The embodiments of the present disclosure will be described withreference to the accompanying drawings. The drawing in which an elementfirst appears is typically indicated by the leftmost digit(s) in thecorresponding reference number.

DETAILED DESCRIPTION

In the following description, numerous specific details are set forth inorder to provide a thorough understanding of the embodiments of thepresent disclosure. However, it will be apparent to those skilled in theart that the embodiments, including structures, systems, and methods,may be practiced without these specific details. The description andrepresentation herein are the common means used by those experienced orskilled in the art to most effectively convey the substance of theirwork to others skilled in the art. In other instances, well-knownmethods, procedures, components, and circuitry have not been describedin detail to avoid unnecessarily obscuring aspects of the invention.

References in the specification to “one embodiment,” “an embodiment,”“an example embodiment,” etc., indicate that the embodiment describedmay include a particular feature, structure, or characteristic, butevery embodiment may not necessarily include the particular feature,structure, or characteristic. Moreover, such phrases are not necessarilyreferring to the same embodiment. Further, when a particular feature,structure, or characteristic is described in connection with anembodiment, it is submitted that it is within the knowledge of oneskilled in the art to affect such feature, structure, or characteristicin connection with other embodiments whether or not explicitlydescribed.

1. OVERVIEW

The present disclosure is directed to a transmitter front-end forwireless chip-to-chip communication, and potentially for other, longerrange communications (e.g., several meters or several tens of meters)between devices. The transmitter front-end can be implemented in an ICchip and includes a distributed power amplifier capable of providing anoutput signal with sufficient power for wireless transmission by anon-chip or on-package antenna to another IC chip or device. As usedherein, “on-chip” means on or within the substrate of the IC chip, and“on-package” means on or within the package used to hold or contain thesubstrate of the IC chip. The distributed power amplifier can be fullyintegrated (i.e., without using external components, such as bond wireinductors) on a monolithic silicon substrate using, for example, acomplementary metal oxide semiconductor (CMOS) process.

The on-chip antenna can be implemented as a phased array of antennassuch that the effective radiation pattern of the phased array ofantennas is reinforced in a desired direction and suppressed in anundesired direction. This helps to reduce the required output power ofthe distributed power amplifier and mitigate interference with otherpotential wireless chip-to-chip communications. As an alternative, anon-package antenna with a higher radiation efficiency can be used inplace of the on-chip antenna, which typically has a comparatively lowerradiation efficiency due to the low resistivity of many IC substrates,such as silicon.

FIG. 1 illustrates an exemplary multi-chip device 100 in whichembodiments of the transmitter front-end described above can beimplemented. Multi-chip device 100 can be, for example, a desktopcomputer, a laptop, a smart phone, a set-top box, or a gaming system. Asshown in FIG. 1, multi-chip device 100 includes a PCB or a module (e.g.,a box) 102 containing multiple IC chips 104-1 through 104-4. In themulti-chip device 100, the IC chips 104-1 through 104-4 are required tocommunicate with each other at high data rates (e.g., in the multi Gb/srange) in order to carry out the designed for functionalities of themulti-chip device 100. However, other data rates (e.g., below a Gb/s)are also possible. It should be noted that, in other embodiments, chips104-1 through 104-4 can be implemented in separate devices (as opposedto being contained on the same PCB, or in the same module, of a device)and can be required to communicate with each other (or other devices) atdistances of several meters or several tens of meters, for example.

In order to perform inter-chip communications, each IC chip 104-1through 104-4 includes a respective transmitter front-end 106-1 through106-4. These transmitter front-ends 106-1 through 106-4 are configuredto amplify the power of a signal with a carrier frequency in the rangeof 30 to 300 GHz or above. The signal to be amplified can be modulatedwith data intended for reception by another one of the IC chips 104-1through 104-4. Signals with frequencies in the range 30 to 300 GHz havea wavelength of ten to one millimeter and are often referred to asmillimeter wave signals. At these small wave lengths, a small lengthon-package or even on-chip antenna can be used to wirelessly transmitthe amplified modulated signal to another one of the IC chips 104-1through 104-4.

In one embodiment, the transmitter front-ends 106-1 through 106-4 areconfigured to amplify a modulated signal with a carrier frequency in therange of 57-64 GHz if the multi-chip device 100 is intended foroperation in the United States or Canada. In another embodiment, thetransmitter front-ends 106-1 through 106-4 are configured to amplify amodulated signal with a carrier frequency in the range 59-66 GHz if themulti-chip device 100 is intended for operation in Japan.

A distributed power amplifier (not shown) is specifically included ineach transmitter front-end 106-1 through 106-4 to amplify the power ofthe modulated signal before being wirelessly transmitted. Thedistributed power amplifiers each include a plurality of poweramplifiers for amplifying the power of the modulated signal and a powercombiner for combining the output signal power of the plurality of poweramplifiers. Distributing the power amplifiers and then combining theirrespective output signal powers allows the distributed power amplifierto be fully integrated on-chip using, for example, a sub-micrometer CMOSprocess, while still providing sufficient output power without breakingdown devices (e.g., transistors) used to implement the individual poweramplifiers. This is because each of the plurality of power amplifiersneed only supply a fraction of the total power. The power combiner canbe further used to perform an impedance transformation, such that theoutput impedances of the plurality of power amplifiers substantiallymatch the impedance of the antenna (also not shown) to which the powercombiner is coupled.

The antenna is used to wirelessly transmit the modulated signal and canbe either implemented on-chip or on-package. When implemented on-chip, aphased array of antennas can be used such that the effective radiationpattern of the phased array of antennas is reinforced in a desireddirection and suppressed in an undesired direction. This helps to reducethe required output power of the distributed power amplifier andmitigate interference with other potential wireless chip-to-chipcommunications.

To prevent collisions and to effectively share the available wirelessbandwidth between the IC chips 104-1 through 104-4, one of the IC chipscan be configured to act as a master device to coordinate transmissionsfrom the other IC chips, configured as slave devices. For example, theIC chip 104-1 can acts as a master device to coordinate transmissionsfrom the other IC chips, such that the available wireless bandwidth iseffectively shared between them and collisions are avoided. The masterIC chip can grant access to the available wireless bandwidth to eachslave IC chip for a limited interval of time—the duration of which canbe determined based on an amount of data that is waiting to bewirelessly transmitted by each slave IC chip. In other embodiments, acontention based media access control protocol can be implemented by theIC chips 104-1 through 104-4 to perform wireless chip-to-chipcommunication. For example, a contention based media access controlprotocol similar to carrier sense multiple access used in Ethernet canbe used. In yet another embodiment, the IC chips 104-1 through 104-4 areassigned non-overlapping transmission bandwidths over which wirelesschip-to-chip communication can be performed.

Referring now to FIG. 2, a block diagram of a transmitter front-end 200is illustrated. The transmitter front-end 200 can be used, for example,to implement one or more of the transmitter front-ends 106-1 through106-4 in FIG. 1. As shown in FIG. 2, the transmitter front-end 200includes a distributed power amplifier 202 and an on-chip or on-packageantenna 204. The distributed power amplifier 202 specifically includes aplurality of power amplifiers 206 and an impedance transformer and powercombiner 208.

In operation, the plurality of power amplifiers 206 are each configuredto independently amplify the power of a signal with a carrier frequencyin the range of 30 to 300 GHz or above. The signal to be amplified canbe modulated with data intended for reception by a nearby IC chip.Signals with frequencies in the range 30 to 300 GHz have a wavelength often to one millimeter and, as noted above, are often referred to asmillimeter wave signals. Thus, as shown in FIG. 2, the power amplifiers206 receive and amplify the power of a signal designated as a modulatedmillimeter wave signal. At these small wave lengths, the short lengthon-chip or on-package antenna 204 becomes possible.

In one embodiment, the modulated millimeter wave signal to be amplifiedby the plurality of power amplifiers 206 has a carrier frequency in therange 57-64 GHz if the device in which the transmitter front-end 200 isimplemented is intended for operation in the United States or Canada. Inanother embodiment, the modulated millimeter wave signal to be amplifiedby the plurality of power amplifiers 206 has a carrier frequency in therange 59-66 GHz if the device in which the transmitter front-end 200 isimplemented is intended for operation in Japan.

After power amplification, the impedance transformer and power combiner208 is configured to combine the amplified millimeter wave signalproduced by each of the plurality of power amplifiers 206. Using aplurality of small sized power amplifiers 206, rather than a singlelarge power amplifier, and then combining their respective output signalpowers allows the distributed power amplifier 202 to be fully integratedon-chip using, for example, a sub-micrometer CMOS process, while stillproviding sufficient output power without breaking down devices (e.g.,transistors) used to implement the plurality of power amplifiers 206.The impedance transformer and power combiner 208 can also be used toperform an impedance transformation, such that the output impedances ofthe plurality of power amplifiers 206 substantially match the impedanceof the on-chip or on-package antenna 204 to which the power combiner iscoupled.

Described below are specific implementations of the transmitterfront-end 200 using both an on-chip antenna and an on-package antenna.The immediate section to follow specifically describes theimplementation of the transmitter front-end 200 using an on-chipantenna. The section following thereafter then describes theimplementation of the transmitter front-end 200 using an on-packageantenna.

2. TRANSMITTER FRONT-END WITH DISTRIBUTED POWER AMPLIFIER AND ON-CHIPANTENNA

FIG. 3 illustrates a schematic diagram of a transmitter front-end 300with an on-chip antenna in accordance with embodiments of the presentdisclosure. The transmitter front-end 300 can be used, for example, toimplement one or more of the transmitter front-ends 106-1 through 106-4in FIG. 1. As shown in FIG. 3, the transmitter front-end includes aplurality of power amplifiers 302 and an impedance transformer andcombiner 304. These two modules together form a distributed poweramplifier as described above. In addition, the impedance transformer andcombiner 304 further includes/forms an on-chip antenna. Thus, theimpedance transformer and combiner 304 is aptly labeled in FIG. 3 as theimpedance transformer, combiner, and on-chip antenna 304. Thetransmitter front-end 300 can be fully integrated on-chip.

The plurality of power amplifiers 302 include N differential poweramplifiers, PA-1 through PA-N, that are each configured to independentlyamplify the power of a signal with a carrier frequency in the range of30 to 300 GHz or above. The signal to be amplified can be modulated withdata intended for reception by a nearby IC chip. Signals withfrequencies in the range 30 to 300 GHz have a wavelength of ten to onemillimeter and are often referred to as millimeter wave signals. Thus,as shown in FIG. 3, the plurality of power amplifiers 302 receive andamplify the power of a signal designated as a modulated millimeter wavesignal. At these small wave lengths, a short length on-chip antennabecomes possible.

After power amplification, the impedance transformer and power combinerportion of module 304 is configured to combine the amplified millimeterwave signal produced by each of the plurality of power amplifiers 302.The impedance transformer and power combiner portion of module 304includes N independent transformers T-1 through T-N. Each of thetransformers T-1 through T-N includes a primary winding and a secondarywinding. The primary windings of the transformers T-1 through T-N areeach coupled to a respective output of one of the plurality of poweramplifiers 302, whereas the secondary windings of the transformers T-1through T-N are coupled together in series. This transformerconfiguration provides electrical isolation between the outputs of theplurality of power amplifiers 302, while allowing their output signalpowers to be added together.

More specifically, the basic ideal transformer equation is given by:

$\begin{matrix}{\frac{V_{S}}{V_{P}} = {\frac{N_{S}}{N_{P}} = \frac{I_{P}}{I_{S}}}} & (1)\end{matrix}$

where V_(P) and V_(S) are the respective voltages in the primary andsecondary windings of a transformer, I_(P) and I_(S) are the respectivecurrents in the primary and secondary windings of the transformer, andN_(S) and N_(P) are the respective number of turns in the secondary andprimary windings of the transformer. Thus, for example, assuming theplurality of power amplifiers 302 are similarly implemented and produceapproximately the same output current I_(P) and voltage V_(P) at theirrespective outputs, it can be shown using EQ. 1 above that the voltageV_(X) across the two ends of the series combination of secondarywindings will be equal to N*V_(s)*(N_(P)/N_(S)), the current I_(X)flowing through the series combination will be equal toI_(S)*(N_(S)/N_(P)), and the total power in the series combination isequal to N*V_(S)*I_(S), which is equal to the sum of the output signalpowers of the plurality of power amplifiers 302.

In addition to power combining, the N transformers T-1 through T-Nfurther transform the output impedance of each of the plurality of poweramplifiers 302. Specifically, the impedance of each of the plurality ofpower amplifiers is approximately transformed from an output impedanceof V_(P)/I_(P) to V_(X)/I_(X) or is approximately transformed accordingto the impedance transformation ratio (V_(P)/I_(P)):(V_(X)/I_(X)), whereV_(P) and I_(P) are the output voltage and current of the poweramplifier, respectively. Assuming the plurality of power amplifiers 302are similarly implemented and produce approximately the same outputcurrent I_(P) and voltage V_(P) at their respective outputs, theimpedance transformation ratio simplifies to approximately 1:N, where Nis the number of transformers. This impedance transformation can be usedto match the typically ideally low output impedance of a poweramplifier, to the comparatively higher input impedance of an antenna,which can be, for example, 50 Ohms.

After power combining and impedance transformation, the modulatedmillimeter wave signal can be wirelessly transmitted using the on-chipantenna further included in module 302 shown in FIG. 3. Specifically,the on-chip antenna is formed by the series combination of secondarywindings of the transformers T-1 through T-N. This series combinationforms a dipole antenna for radiating the modulated millimeter wavesignal to a nearby IC chip. In one embodiment, the antenna isimplemented using a metal layer formed on the substrate of the IC chip.

Referring now to FIG. 4, a schematic of a power amplifier 400 inaccordance with embodiments of the present disclosure is illustrated.The power amplifier 400 can be used, for example, to implement one ormore of the plurality of power amplifiers 302 in FIG. 3. As shown inFIG. 4, the power amplifier 400 includes a differential input stage 402,a cascode stage 404, and an inductor 406. The differential input stage402 is implemented using two NMOS transistors and is configured toreceive at the gates of the NMOS transistors a differential signal to beamplified. Cascode stage 404 is further implemented using two NMOStransistors and is configured to provide isolation between the inputstage 402 and the output of the power amplifier 400, which is takendifferentially across the inductor 406. Inductor 406 is generally usedto resonate out parasitic capacitances associated with the transistorsof the input stage 402. In one embodiment, inductor 406 can beimplemented, at least in part, by the primary winding of a transformerin module 304 illustrated in FIG. 3.

It should be noted that the power amplifier 400 is only one examplepower amplifier that can be used to implement one or more of theplurality of power amplifiers 302 in FIG. 3. Other power amplifierconfigurations using, for example, different transistors or not using acascode stage are also possible.

Referring now to FIG. 5, an exemplary integrated circuit layout of animpedance transformer, combiner, and on-chip antenna 500 is illustratedin accordance with embodiments of the present disclosure. The impedancetransformer, combiner, and on-chip antenna 500 can be used, for example,to implement the impedance transformer, combiner, and on-chip antenna300 in FIG. 3.

As shown in FIG. 5, impedance transformer, combiner, and on-chip antenna500 includes N transformers T-1 through T-N. Each transformer T-1through T-N includes two spiral inductors that form its windings. Thisis further illustrated by the blown up illustration of exemplarytransformer T-1 shown on the left side of FIG. 5. In the blown upversion of the transformer T-1, it can be seen that the transformer T-1includes a first spiral inductor 502 with two ends 506 and 508, and asecond spiral inductor 504 with two ends 510 and 512. Although the twospiral inductors 502 and 504 are shown in FIG. 5 as being laid out flatnext to each other for ease of illustration, in actual implementationthe two spiral inductors 502 and 504 are stacked, with one of the spiralinductors on top of the other. In an integrated circuit, the two spiralinductors can be stacked by using different metal layers. For example,the spiral inductor 502 can use an eighth metal layer on an integratedcircuit substrate, and the spiral inductor 504 can use a ninth metallayer that is positioned above the eighth metal layer on the integratedcircuit substrate.

In the embodiment of FIG. 5, spiral inductors 502 and 504 each includeonly a single loop. In other embodiments, spiral inductor 502 and/orspiral inductor 504 can be implemented with more than one loop.

Referring now to FIG. 6, a phased array of transmitter front-ends 600 isillustrated in accordance with embodiments of the present disclosure.The phased array of transmitter front-ends 600 includes tour transmitterfront-ends 602-1 through 602-4 that are each implemented in asubstantially similar manner as transmitter front-end 300 illustrated inFIG. 3. However, each transmitter front-end 602-1 through 602-4includes, in addition to a distributed power amplifier and on-chipantenna as shown, a respective one of phase shifters 604-1 through604-4. Each transmitter front-end 602-1 through 602-4 is configured totransmit the same modulated millimeter wave signal, albeit withpotentially different phases relative to one another.

In specific operation, the phase shifters 604-1 through 604-4 areconfigured to independently adjust a phase of the modulated millimeterwave signal to be amplified and transmitted by the respectivetransmitter front-end to which it is coupled. For example, the modulatedmillimeter wave signals amplified by the plurality of power amplifiersin transmitter front-end 602-1 are configured to be combined, using acombiner made up of transformers as discussed above in FIG. 3,substantially in phase with each other such that they constructivelycombine before being wirelessly transmitted. Phase shifter 604-1 isconfigured to modify the phase of this constructively combined signalrelative to the constructively combined signal of one or more of theother transmitter front-ends 602-2 through 602-4. By adjusting therelative phases of the constructively combined signals produced andwirelessly transmitted by two or more of the transmitter front-ends602-1 through 602-4, the wireless transmitted signals can be made tointerfere with each other (constructively and destructively) such thatthe effective radiation pattern of the phased array of transmitterfront-ends 600 is reinforced in a desired direction and suppressed in anundesired direction. The desired direction can be, for example, thedirection of a nearby IC chip intended to receive the wirelesslytransmitted modulated millimeter wave signal, or even the direction of aremotely located device (or IC chip within the remotely located device)several meters or several tens of meters away. This directionality helpsto reduce the required output power of the distributed power amplifiersof the transmitter front-end 602-1 through 602-4 and mitigateinterference with other potential wireless chip-to-chip communications.

A controller (not shown) can be configured to control the phase shifters604-1 through 604-4 to provide the desired directionality. Thecontroller can determine the phase shifts based on the relativepositioning of the antennas of the transmitter front-ends 602-1 through602-4 and the desired direction in which the wireless transmitted signalshould be directed.

It should be noted that, although four transmitter front-ends 602-1through 602-4 are shown in FIG. 6, other numbers of transmitterfront-ends 602-1 through 602-4 can be used. For example, two transmitterfront-ends or six transmitter front-ends can be used.

3. TRANSMITTER FRONT-END WITH DISTRIBUTED POWER AMPLIFIER AND ON-PACKAGEANTENNA

FIG. 7 illustrates a schematic diagram of a transmitter front-end 700with an on-package antenna in accordance with embodiments of the presentdisclosure. The transmitter front-end 700 can be used, for example, toimplement one or more of the transmitter front-ends 106-1 through 106-4in FIG. 1.

As shown in FIG. 7, the transmitter front-end includes a distributedpower amplifier 702 for amplifying the power of a modulated millimeterwave signal to be wireless transmitted to a nearby IC chip, or even to aremotely located device (or IC chip within the remotely located device)several meters or several tens of meters away. The distributed poweramplifier 702 is substantially similar to the distributed poweramplifier 302 described above in FIG. 3 and includes a plurality ofpower amplifiers and an impedance transformer and combiner made up oftransformers. Each of the primary windings of the transformers arecoupled to a respective output of one of the plurality of poweramplifiers, and the secondary windings of the transformers are coupledtogether in a loop configuration as shown in FIG. 7. This loop isconfigured to inductively couple the combined output signal power of thepower amplifiers in the distributed power amplifier 702 to an on packageantenna 704. The on package antenna 704 forms a dipole antenna that isconfigured to radiate the combined output signal power such that anearby IC chip can receive the radiated signal.

4. CONCLUSION

The present disclosure has been described above with the aid offunctional building blocks illustrating the implementation of specifiedfunctions and relationships thereof. The boundaries of these functionalbuilding blocks have been arbitrarily defined herein for the convenienceof the description. Alternate boundaries can be defined so long as thespecified functions and relationships thereof are appropriatelyperformed.

1-8. (canceled)
 9. A transmitter front-end for wireless communications,the transmitter comprising: an antenna included within an array ofantennas integrated on a chip; a phase shifter configured to adjust aphase of a signal to be transmitted by the antenna to provide a phaseadjusted signal such that an effective radiation pattern of the array ofantennas on the chip is reinforced in a desired direction and suppressedin undesired directions; a first power amplifier configured to amplifythe phase adjusted signal for transmission by the antenna to provide afirst amplified version of the phase adjusted signal at an output of thefirst power amplifier; a second power amplifier configured to amplifythe phase adjusted signal for transmission by the antenna to provide asecond amplified version of the phase adjusted signal at an output ofthe second power amplifier; and an impedance transformation and powercombining module comprising a first transformer and a secondtransformer, wherein a primary winding of the first transformer iscoupled to the output of the first power amplifier, a primary winding ofthe second transformer is coupled to the output of the second poweramplifier, and a secondary winding of the first transformer is coupledin series with a secondary winding of the second transformer.
 10. Thetransmitter front-end of claim 9, wherein the antenna is coupled to thesecondary winding of the first transformer and to the secondary windingof the second transformer.
 11. The transmitter front-end of claim 9,wherein the secondary winding of the first transformer and the secondarywinding of the second transformer form, at least in part, the antenna.12. The transmitter front-end of claim 9, wherein the primary winding ofthe first transformer is configured to resonate out parasiticcapacitances associated with the first power amplifier.
 13. Thetransmitter front-end of claim 9, wherein both the primary winding ofthe first transformer and the secondary winding of the first transformerare implemented using spiral inductors on the chip.
 14. The transmitterfront-end of claim 9, wherein the antenna is a dipole antenna.
 15. Thetransmitter front-end of claim 9, wherein the signal has a wavelength often to one millimeter. 16-20. (canceled)
 21. A transmitter front-end forwireless communications, the transmitter comprising: an antennaintegrated on a package of a chip; a first power amplifier configured toamplify a signal for transmission by the antenna to provide a firstamplified version of the phase adjusted signal at an output of the firstpower amplifier; a second power amplifier configured to amplify thesignal for transmission by the antenna to provide a second amplifiedversion of the phase adjusted signal at an output of the second poweramplifier; and an impedance transformation and power combining modulecomprising a first transformer and a second transformer, wherein aprimary winding of the first transformer is coupled to the output of thefirst power amplifier, a primary winding of the second transformer iscoupled to the output of the second power amplifier, and a secondarywinding of the first transformer is coupled in series with a secondarywinding of the second transformer to form a series connection.
 22. Thetransmitter front-end of claim 21, wherein the series connection isconfigured to magnetically couple the impedance transformation and powercombining module to the antenna.
 23. The transmitter front-end of claim21, wherein the primary winding of the first transformer is configuredto resonate out parasitic capacitances associated with the first poweramplifier.
 24. The transmitter front-end of claim 21, wherein both theprimary winding of the first transformer and the secondary winding ofthe first transformer are implemented using spiral inductors on thechip.
 25. The transmitter front-end of claim 21, wherein the antenna isa dipole antenna.
 26. The transmitter front-end of claim 21, wherein thesignal has a wavelength of ten to one millimeter.
 27. A transmitterfront-end for wireless communications, the transmitter comprising: anantenna included within an array of antennas integrated on a chip; aphase shifter configured to adjust a phase of a signal to be transmittedby the antenna to provide a phase adjusted signal such that an effectiveradiation pattern of the array of antennas on the chip is reinforced ina desired direction and suppressed in undesired directions; and animpedance transformation and power combining module comprising a firsttransformer and a second transformer, wherein a primary winding of thefirst transformer is coupled to an output of a first power amplifierconfigured to amplify the phase adjusted signal, a primary winding ofthe second transformer is coupled to an output of a second poweramplifier configured to amplify the phase adjusted signal, and asecondary winding of the first transformer is coupled in series with asecondary winding of the second transformer.
 28. The transmitterfront-end of claim 27, wherein the antenna is coupled to the secondarywinding of the first transformer and to the secondary winding of thesecond transformer.
 29. The transmitter front-end of claim 27, whereinthe secondary winding of the first transformer and the secondary windingof the second transformer form, at least in part, the antenna.
 30. Thetransmitter front-end of claim 27, wherein the primary winding of thefirst transformer is configured to resonate out parasitic capacitancesassociated with the first power amplifier.
 31. The transmitter front-endof claim 27, wherein both the primary winding of the first transformerand the secondary winding of the first transformer are implemented usingspiral inductors on the chip.
 32. The transmitter front-end of claim 27,wherein the antenna is a dipole antenna.
 33. The transmitter front-endof claim 27, wherein the signal has a wavelength of ten to onemillimeter.